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CNC machine tools, known for their high precision, efficiency, and automation, are particularly well-suited for processing irregular parts.
Due to the complex shapes of these parts and the challenges they present in manufacturing, advanced processing technologies are essential to maintain quality and efficiency.
However, the intricate nature of irregular parts necessitates that the processing techniques employed by CNC machine tools be carefully adjusted and optimized to achieve the desired outcomes.
Difficulties in processing
1. Complex process
2. High precision requirements
3. Low processing efficiency
Irregular parts have complex structures. When processing them, CNC machine tools often require more complex programming and tool path planning.
This ensures the desired shape is accurately processed. As a result, processing time and difficulty increase, leading to relatively low efficiency.
Process design
1. Selection of machining tools
Since the cutting tool is used for extended periods, its cutting performance and service life are crucial factors when selecting the tool.
Typically, an equilateral diamond-shaped coated insert with a specific angle (80° or 35°) is chosen for better cutting results.
The 80° equilateral diamond-shaped insert is more suitable for processing harder materials or situations that require higher cutting force.
It provides greater tip strength and cutting force. On the other hand, the 35° insert is better for machining softer materials or situations where finer cutting is needed.
It offers less cutting force and provides better surface quality.
We usually use three methods to determine if a processing tool should be replaced:
(1)Check the wear on the tool’s flank surface. If there are serious wear marks, such as coating peeling, severe wear, or noticeable changes in coating color, we should replace the tool promptly.
(2)Inspect the surface of the processed parts. Under the same cutting conditions, if the chip shape changes significantly.
Such as from long strips to short pieces or chips—or if the chip color changes from silver to white, yellow, or black, it indicates that the tool is severely worn.
(3)Judge by the sound of the processing. If the tool produces unusual sounds, such as loud noise, harsh sound, or a noticeable change in pitch during cutting, we should replace the tool immediately.
2. Selection of cutting parameters
The selection of cutting parameters should consider the hardness and toughness of the processed material. For harder materials, the tool must withstand greater cutting forces.
Therefore, cutting parameters need to be increased to improve efficiency and ensure tool life.
For tougher materials, cutting parameters should be reduced to prevent excessive cutting force from deforming the workpiece or damaging the tool.
Additionally, the tool’s material and type must be considered. Different tools have varying wear resistance and rigidity, so cutting parameters should be adjusted accordingly.
Carbide tools can handle higher cutting parameters, while coated tools require lower parameters to avoid coating peeling.
The tool type also affects parameter selection. Milling and turning tools, for example, have different cutting parameters.
Furthermore, processing requirements play a crucial role in selecting the appropriate cutting parameters.
3. Design of mechanical fixtures
The design of the fixture also needs to take into account the size of the parts. Parts with irregular sizes may have problems such as poor symmetry and difficulty in positioning in the fixture design.
When designing a fixture, it is necessary to consider how to ensure that the position of the part in the fixture is accurate through appropriate positioning methods.
The material and surface treatment of the fixture are also factors that cannot be ignored.
The material of the fixture should have sufficient hardness and strength to ensure that the fixture does not deform or damage during long-term use.
At the same time, the fixture’s surface treatment should consider the surface requirements of the parts. This helps prevent damage or wear to the parts during the clamping process.

4. Determination of the benchmark
Carefully studying the drawings and technical requirements of the parts is crucial.
This helps determine key parameters such as geometry, dimensional tolerance, and surface roughness requirements.
These parameters serve as the basis for establishing the benchmark, and staff must follow these requirements strictly.
In the actual processing process, determining the benchmark involves several aspects:
(1)Positioning benchmark: This refers to determining the part’s specific position and direction on the CNC machine tool.
(2)Processing benchmark: This defines the relative position between the part, the tool, and the workpiece table during processing.
Accurate determination of both the positioning and processing benchmarks ensures the part remains stable during machining, preventing deviation and ensuring dimensional accuracy.
Additionally, the process benchmark is crucial. This includes setting processing parameters such as cutting speed, feed speed, and cutting depth.
These parameters directly affect the surface quality and processing efficiency of the part.
5. Workpiece clamping problem
Workpieces of different shapes and sizes require different clamping methods to prevent displacement or deformation during processing. This ensures processing accuracy and quality.
When clamping the workpiece, staff must ensure proper alignment. This means confirming that the workpiece’s position and direction within the fixture are correct to minimize processing errors.
Additionally, the size and direction of the clamping force must be carefully considered. The workpiece must be securely held to prevent movement or deformation during processing.
It is also important to ensure that the contact surface between the workpiece and fixture is fully engaged, and that the clamping force is evenly distributed.
Poor surface contact or uneven clamping force can lead to workpiece displacement or deformation, which negatively affects processing accuracy.
When installing the fixture on a self-centering chuck, the rotation axis of the clamp and the main axis of the lathe must be controlled within 0.01mm to ensure precision.
6. Processing wheel frame issues
When selecting a processing wheel frame, consider the shape, size, weight, and processing requirements of the parts. The frame should be stable and reliable to prevent displacement or deformation during processing.
When installing the processing wheel frame, ensure it is securely connected to the workbench of the CNC machine tool. This will avoid any shaking or displacement during processing.
Additionally, adjust the height, angle, and position of the processing wheel frame according to the part’s shape and processing requirements. This ensures that the parts are properly fixed and processed.
The material and surface treatment of the processing wheel frame are also important. The frame should be made of high-strength, high-hardness materials to prevent deformation or damage during processing.
The surface of the frame should be smoothed to reduce friction resistance when in contact with the parts, improving processing accuracy.
During processing, regularly check the frame’s stability. If the frame is found to be loose or deformed, stop and inspect it immediately to avoid affecting part processing.

Conclusion
CNC machine tools are advanced processing equipment that are highly suitable for processing irregular parts due to their high precision, efficiency, and automation.
However, researching CNC machine tool processing technology for irregular parts is a complex task.
Success can be achieved through the careful selection of processing tools and cutting parameters, scientific design of mechanical fixtures, and accurate determination of benchmarks.
At the same time, attention should be given to workpiece clamping and processing wheel frames.
By improving these aspects, we can enhance the processing efficiency and quality of irregular parts, reduce production costs, and increase the competitiveness of enterprises.